Pharmaceutical company AstraZeneca and Oxford University have resumed clinical trials of their COVID-19 vaccine candidate in the United Kingdom after a brief global pause in testing.

AstraZeneca put a hold on its COVID-19 clinical trials worldwide this week while it investigated an adverse reaction in a trial participant in the U.K., who developed a serious neurological problem after receiving the vaccine.

AstraZeneca and Oxford declined to provide more information about what happened to the patient who fell ill.

"We cannot disclose medical information about the illness for reasons of participant confidentiality, we are committed to the safety of our participants and the highest standards of conduct in our studies and will continue to monitor safety closely." Oxford said.

The vaccine developers said trials would resume across all U.K. clinical trial sites, but it was not immediately clear when or if other sites would resume. AstraZeneca is running several large trials around the world, including one in the U.S.

A standard review process triggered the study pause on Sunday, the groups said, and an independent safety review committee and national regulators reviewed the group's safety data.

"The independent review process has concluded and following the recommendations of both the independent safety review committee and the UK regulator, the (Medicines and Healthcare Products Regulatory Agency), the trials will recommence in the UK," Oxford said in a statement Saturday.

"From a U.S. perspective, the company will continue to work with health authorities across the world, including the FDA, and be guided as to when other clinical trials can resume to provide the vaccine broadly, equitably and at no profit during this pandemic," AstraZeneca spokesperson Michele Meixell told USA TODAY.

Pausing a vaccine trial is not uncommon, health experts say.

"Globally some 18,000 individuals have received study vaccines as part of the trial. In large trials such as this, it is expected that some participants will become unwell and every case must be carefully evaluated to ensure careful assessment of safety," Oxford said.

In the U.S., Moderna and Pfizer are also conducting Phase 3 clinical trials of their vaccine candidates.

Pfizer on Saturday announced plans to extend its trial from 30,000 to 44,000 participants to "increase population diversity." The expansion would allow the trial to include adolescents as young as 16 and people with chronic, stable HIV, hepatitis C, or hepatitis B infection, the company said in a press release.

Source:

https://www.bbc.com/news/uk-54132066

https://www.usatoday.com/story/news/health/2020/09/12/astrazeneca-oxford-covid-vaccine-resume-pause-illness/5779202002/